This Golden Potlatch parade image is unsigned but has Otto's distinctive writing. He took many photos of the Golden Potlatch parades held from 1911 to 1913; not all of them were signed. This postcard shows the first parade; it is dated 1911 on the front and has a postmark of August 7, 1911 on the back.
Note the spelling of "Seattle." Otto was writing captions backwards on the glass negatives, and sometimes missed letters or strokes within letters.